You cannot trust the readings of a narrow band O2 sensor @ WOT

Thats what widebands are for.

 

I know that is why I said it's more of a "guestimation" gauge.

 

Oh, thought you had LE3 heads from a previous post... n/m, those #'s aren't the ones I saw posted before...

Like I said before, a trip to the dyno is in order to see what the heck is goin' on. Did madz28 or pcmforless do your tune? As long as you got what you ordered I can't see it being too off.. I had a pcmforless tune in mine and ran 112.8 traps w/ it cam only.

 

An AFPR can make the tuners job a lot more difficult unless you are very sure you have it set for the pressure he had in mind.
How good is the rebuild what was the target compression ratio?
MOST shops are unfamiliar with the LT1 and it's abnormally high compression ratios unless you truely enlighten them as to what stock is and convince them to go higher they will likely put it together for 9.xx:1 which would be a bad thing with that much cam. You didn't list a shop or any details so I am just guessing here. Had you used a vendor here that knew the LT1 I figure you probably would have mentioned that.

 

My guy is a LTX/LSX specialist, he has a '98 Z28 him self. The compression ratio on this motor is near stock at 10.4:1... there was nothing special in mind with this motor, it was just to get the car up and running again.


Those numbers that you are thinking of are my buddies stage 3 LT1 heads, stock LT1 castings, I know which ones you are thinking about.

 

Specialist or not did he know exactly what you are running for pressure? You could have the best tuner ever but if you have the FP set for other than what he figured for things will be wrong.

 

The tuner tuned for stock FP and my car is running a little less than stock, but the car is still pig rich.